According to the Portuguese Institute of the Sea and the Atmosphere (IPMA), the four warmest months of September on a global scale occurred in 2020, 2021, 2019 and 2016.
In Portugal, according to the monthly climatological bulletin, which presents information only for the continental territory, last September "was classified as normal in relation to air temperature and rainy in relation to precipitation".
The report states that "the drought situation remains only in the regions south of the Tagus, where there has been a decrease in its intensity", with a light to moderate drought now prevailing, which covers less than half of the continental territory (42.8 percent).
In September, the average rainfall amount, 66.8 millimetres, was higher than normal for the 1971-2000 reference period, being the fourth highest since 2000.
The maximum air temperature was "almost always close to or below the monthly normal value".
The hottest day was 5 September, in Fonte Boa, Santarém, where the thermometers recorded a maximum temperature of 39.8°C, while the coldest day was 29 September, in Lamas de Mouro, Melgaço, where the minimum temperature reached 2.5°C.
The rainfall record for the month under review was set on 13 September, in Cernache, Coimbra, with 81.6 millimetres of rain.
In Europe, September 2021 was characterised as being drier than average in "large parts" of the southern region and wetter than average "in western France, the Iberian Peninsula and along the coast of the Black Sea", the IPMA adds.
On the European continent, most western regions recorded "well above average temperature values", with the UK having the second "hottest ever" September.
In the eastern region there were "below average temperature values", with the Finnish capital, Helsinki, having the "coldest since 1997" September.